King George V did it in 1919 and since then, each year a member of the Royal family places a wreath at the foot of the Cenotaph monument in Whitehall, London in honour of those who died in the great wars. And each Remembrance Day the sad, dignified ritual is photographed.
Professor Tim Sparks is fascinated by the use of long term data to detect climate change impacts. He started examining old photos of the ceremony and realized that the state of those plane trees has changed dramatically.
An examination of photos dating back to 1919 shows that the trees are keeping their leaves much longer now. In the old photos the branches were bare on November 11. But in the last twenty years the photos show the plane trees with full leafy foliage.
Professor Sparks was looking for a way to track autumn foliage changes as a result of climate change. As he said "Unlike spring, there are few long-running records of autumn events. Autumn is highly variable compared to spring, and it’s harder to detect the changes that are going on,"
Spending hours trawling the internet for photos, newspapers and films, he was able to assemble a collection of photos over the years, all of the same view of the Cenotaph. Apparently the changes in the past 20 years have been the most notable. This fits with weather predictions that this autumn in the UK has been the warmest on record. So far, temperatures are 3.5C above normal across the country.
Sparks is an expert on the study of phenology, "the timing of naturally recurring events as diverse as ice-melt, bear hibernation, bird migration, insect flight, plant flowering and lawn cutting."
He has developed quite a specialty in this area and recently noted that UK fruit trees are ripening earlier than before. As reported, "native trees in Britain are producing ripe fruit 18 days earlier than they were a decade ago. In addition, BBC News says acorns are ripening 13 days earlier than in at the turn of the 21st century, while rowan berries are ripening a full month earlier than normal."
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